There is a direct correlation between those who have lack of sunlight, or vitamin D, and MS. If you could go outside for about 30 minutes once a day, and just take a walk around the block, and get sun on your arms it can give you a large dose of vitamin D which also lifts your mood. And if you have been sitting mostly at the computer all these years, that could be your posture from doing that.

You are very young and I bet you could improve your posture pretty easily by doing gentle stretching exercises and just think about your posture or maybe get a better chair or support for your back when you're at the computer.